Aerosol-based insecticide compositions and methods of using the same

ABSTRACT

An aerosol-based insecticide composition comprising an active ingredient, such as deltamethrin, and a suitable carrier is disclosed as well as a method for its use. The insecticide composition may optionally contain one or more surfactants. Deltamethrin is preferably used as the active ingredient in the insecticide composition because of its tolerance for use on food. Furthermore, it has also been determined that deltamethrin is non-repellant to termites.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of application Ser.No. 09/778,591, filed Feb. 7, 2001, which is herein incorporated byreference in its entirety, now pending.

FIELD OF THE INVENTION

[0002] This invention relates to novel chemical insecticide formulationsthat having a recognized tolerance of the active ingredients for use infood and methods for preparing and using said formulation. Inparticular, this invention is directed to a novel insecticideformulation that is suited for aerosol-based applications, includingaerosolized foam applications.

BACKGROUND OF THE INVENTION

[0003] Insecticides generally refer to a wide range of environmentalinterventions that have as their objective, the reduction of insectpests to an acceptable level from a particular area. Specific controltechniques include chemical, physical and biological mechanisms,however, this invention is directed towards chemical insecticides.

[0004] The great majority of insecticides used today comprise syntheticcompounds that affect the nervous system of insects on contact.Historically, chlorinated hydrocarbons such as DDT, chlordane andtoxaphene had been used, but many of these compounds have been banned inthe U.S. or fallen out of favor. Organophosphates, such as malathion,parathion, and dimethoate are currently widely used active ingredientsfor insecticides. A wide range of biological insecticides are also inuse today. Although insecticides are widely used and provide greatbenefits to the users, environmental and social costs of widespread usecan be high. For example, the use of DDT has been banned in the U.S.since 1973 because of its long-range environmental and human safetyimpacts, despite the fact that it functioned well as an insecticide.

[0005] A variety of insecticide formulations are known. For example,U.S. Pat. No. 6,159,956 discusses the preparation and use ofdifluorovinylsilane as an insecticide. Likewise, U.S. Pat. No. 6,162,799discusses the preparation and use of certain naphthoquinone derivativesas pesticides and U.S. Pat. No. 6,124,466 promotes the use of certainnitroisourea derivatives for their insecticidal activity.

[0006] In formulating insecticides, a variety of considerations need tobe weighed. First, obviously, one must utilize an active ingredient, oringredients, that possess the appropriate degree of insecticidalactivity towards the group of insects it is intended to be used against.However, the active ingredient must be such that it is safe for humanuse and reasonably environmentally safe, when being applied according toits instructions. One means of ensuring that the active ingredient issafe for human use is to use an active ingredient(s) that has arecognized tolerance for use on food, thus allowing for use in foodpreparation areas. Preferably, the active ingredient(s) is susceptibleto being naturally degraded by organisms in the soil, or otherwise, uponextended exposure to the environment.

[0007] Typically, the active ingredient(s) in an insecticide formulationare solublized or dispersed in a carrier, which will generally make upthe bulk of the formulation. A variety of carrier characteristics, suchas solubility or dispersability of the active ingredient in the carrier,toxicity of the carrier, odor, volatile organic content,biodegradability, and flammability, need to be considered in the choiceof an effective carrier. Preferably the active ingredient(s) will bedissolved by, or dispersed in, the carrier during storage so that nomixing is required just prior to use. Carrier choice can also be limitedby the need to aerosolize or foam the insecticide. Frequently there aretrade-offs among these characteristics in choosing the most effectiveoverall carrier.

[0008] Most preferably, the carrier(s) can dissolve the activeingredient(s) into an insecticide formulation that achieves theappropriate level of insecticidal activity, while at the same timeposing little or no danger to human health and the environment when usedas intended. The formulation should also possess low odor, have lowvolatile organic content, be biodegradable and relatively non-flammable.

[0009] It is also desired that the active ingredient in the insecticidecomposition is non-repellant to termites. By “non-repellant” what ismeant is that the termites do not detect the active ingredient and willreadily move through the treated zone, picking up a lethal dose of theactive ingredient.

SUMMARY OF THE INVENTION

[0010] The inventors herein have discovered an insecticide formulationcomprising:

[0011] (a) an active ingredient having a tolerance for use on food or ina food preparation area; and

[0012] (b) a suitable carrier;

[0013] wherein the insecticide formulation containing an effectiveamount of an aerosol propellant that is compatible with the insecticideformulation and optionally, one or more foaming agents.

[0014] The insecticide compositions of the invention can provide aneffective insecticide that has low volatile organic content and odor.

DETAILED DESCRIPTION OF THE INVENTION

[0015] The inventors herein have discovered that effective insecticidescan be formulated which promote most advantages typically sought ininsecticides. In particular, the insecticide formulations of thisinvention provide an excellent level of insecticidal activity, while, atthe same time, posing low levels of risk to human safety and theenvironment when used as directed. Furthermore, the active ingredient(s)in the insecticide formulations have a tolerance allowing for their useon food and in food preparation areas. In addition, the formulationshave low levels of objectionable odors, low volatile organic content andlow flammability.

[0016] The insecticide formulations of the instant invention can bedispersed in an appropriate carrier and used in aerosol applications. Inan alternate embodiment, the insecticide formulation further comprisesone or more foaming agents (surfactants). Depending on the particularapplication, different solvents and/or aerosols may be used. When usedin an aerosol application not containing foaming agent(s) of theinvention, compositions of the invention can be used without the needfor mixing directly prior to use. However, aerosol formulationscontaining the foaming agents do require mixing (i.e., shaking)immediately prior to use. In addition, if the formulations containingfoaming agents are used for an extended time, they may requireadditional mixing at periodic intervals during use.

[0017] These and other objects can be accomplished by formulating aninsecticide comprising:

[0018] (a) an active ingredient having a tolerance for use on food or ina food preparation area; and

[0019] (b) a suitable carrier;

[0020] wherein the insecticide formulation containing an effectiveamount of an aerosol propellant that is compatible with the insecticideformulation and optionally, one or more foaming agents.

[0021] Pyrethrins, and in particular deltamethrin, anα-cyano-pyrethroid, are the preferred active ingredients of theinsecticide formulation of this invention and provides the formulationwith its insecticidal activity. The International Union of Pure andApplied Chemistry name for Deltamethrin is (S)-α-cyano-3-phenoxybenzyl(1R)-cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-carboxylate.Deltamethrin is produced by AgrEvo Environmental Health of 95 ChestnutRidge Road, Montvale, N.J., 07645. The concentration of deltamethrin inthe insecticide formulation may range from 0.01 to 2% by weight of theinsecticide without propellant, but is preferably from 0.01 to 0.5% byweight of the insecticide without propellant and most preferably from0.10 to 0.30% by weight of the insecticide without the propellant.Surprisingly, the inventors have discovered that deltamethrin isnon-repellant to termites, meaning that termites do not detect thedeltamethrin in the treated area and will readily move through thetreated area, picking up a lethal dose of the deltamethrin.

[0022] One of the objects of the invention is to create an insecticideformulation that can be used in food handling establishments where foodis prepared. A benefit of using deltamethrin (or another similarpyrethrin) is that it has a tolerance allowing for its use on food or ina food preparation area. A list of active ingredient that have atolerance allowing for their use on foods and in food preparation areasis codified at 40 C.F.R. Part 180. The tolerance of pyrethrins in food,including deltamethrin, is codified specifically at 40 C.F.R. 180.128.

[0023] In addition to the deltamethrin, the insecticides of thisinvention may also comprise additional active ingredients that arecertified as usable in a food environment. Such active ingredientsinclude, for example, Pyrethrins and Piperonyl Butoxide. Both of theforegoing are available from Prentiss, Inc. of Rowell, Ga. If used, theconcentration of these additional active ingredients in the insecticidemay preferably range from 0.05 to 1.0 percent by weight of theinsecticide without propellant.

[0024] When the insecticide formulation does not contain foamingagent(s), the preferred carrier for use in the invention is aniso-paraffinic hydrocarbon carrier. The concentration of aromatichydrocarbons in the carrier is desirably less than 1% by weight,preferably less than 0.5% by weight and most preferably less than 0.1%by weight.

[0025] The iso-paraffinic hydrocarbon carrier is a blend of aliphatichydrocarbons, preferably branched, with the general empirical formula ofC_(n)H_(2n+2). Preferably, the hydrocarbon carrier comprises a mixtureof C₈ and C₉ branched iso-paraffinic hydrocarbons. The concentration ofaromatic hydrocarbons in the carrier is desirably less than 1% byweight, preferably less than 0.5% by weight and most preferably lessthan 0.1% by weight. Preferably, the concentration of non-aromaticcompounds with carbon-carbon double bonds, such as alkenes,cycloalkenes, dienes and cyclodienes, is less than about 2% by weight ofthe carrier, most preferably, less than about 1% by weight of thecarrier. Particularly, preferred iso-paraffinic hydrocarbons are soldunder the tradename ISOPAR® by the Exxon Chemical Company, P.O. Box3272, Houston, Tex. 77253-3272. A particularly preferred ISOPAR®solvent, ISOPAR E®, is a mixture of C₈ and C₉ branched iso-paraffinichydrocarbons. Other iso-paraffinic solvents are sold by the Condea VistaCompany of Houston, Tex. under the tradename, VISTA LPA®. These solventscontain iso-paraffins, but also contain higher concentrations of otherparaffins and naphthenic hydrocarbons (as used herein naphthenichydrocarbons means cyclic hydrocarbons that are not aromatic in naturesuch as cyclohexane). A combination of the ISOPAR® and VISTA LPA®solvents produces an insecticide that effectively dissolves thedeltamethrin with relatively low volatile organic content.

[0026] The concentration of iso-paraffinic carrier in the insecticideformulation may range from about 80% to 99.98% by weight of theinsecticide without propellant, but preferably ranges from about 97% to99.98% by weight of the insecticide without propellant and mostpreferably the insecticide comprises substantially only thedeltamethrin, the iso-paraffinic carrier, and if desired the aerosolpropellant. As noted the iso-paraffinic carrier may preferably comprisea mixture of iso-paraffinic solvents with the total concentration of themixture within the foregoing concentration parameters. Theiso-paraffinic carrier of this invention acts as an excellent solventfor deltamethrin as well as the optional additional active ingredientslisted above. It is believed that one of the reasons these formulationshave been found to be non-repellant to termites is because the uniquelinear evaporation-rate properties of Isopar E promote an evendispersion of solute residue on surfaces, rather than recrystalizationinto larger more easily detectable particles.

[0027] The deltamethrin is dissolved in the iso-paraffinic hydrocarboncarrier with mixing. Once effectively mixed with the iso-paraffinichydrocarbon carrier, the deltamethrin will generally remain in solutionand no further mixing or shaking of the product will be required. Someiso-paraffinic hydrocarbon carrier formulations of the invention mayrequire heat in order to effectively dissolve the deltamethrin. However,other iso-paraffinic hydrocarbon carrier formulations of the inventioncan effectively dissolve the deltamethrin without heat. Once dissolved,the deltamethrin/carrier combination can be charged into an emptyaerosol can, the valve installed, and the aerosol propellant added.

[0028] When the insecticide formulation further comprises one or morefoaming agents, the preferred carrier is deionized water rather than aniso-paraffinic hydrocarbon carrier. In this instance, the concentrationof the deionized water is 55% to 75% by weight of the insecticidecomposition, preferably 60% to 70% by weight of the insecticidecomposition.

[0029] Foaming agents that may be usable in formulations of theinvention include sodium laureth sulfate, cocamide DEA, andcocamidopropyl betaine. Preferably the sodium laureth sulfate, cocamidediethanol amide, and cocamidopropyl betaine are used in combination.Most preferably the foaming agent of the invention consists of 10percent by weight cocamide DEA, 50 percent by weight sodium laurethsulfate, and 40 percent by weight cocamidopropyl betaine. Theconcentration of the foaming agent(s) in the insecticide composition is10% to 25% by weight, more preferably 15% to 20% by weight of thecomposition.

[0030] A suitable source of sodium laureth sulfate is available fromStepan Company under the tradename Steol® 4N. A suitable source ofcocamide DEA is available from Stepan Company under the tradename Ninol®40-CO. A suitable source of cocamidopropyl betaine is available fromStepan Company under the trade name Amphosol® CG.

[0031] The aerosol insecticide formulations of the invention arecompatible with a variety of aerosol propellants. When the formulationsdo not contain the one or more surfactants, the inventors have foundcarbon dioxide, liquefied petroleum gasses, hydrofluorocarbons, andknown chlorofluorocarbon replacements to be particularly useful aerosolpropellants. One skilled in the art would know that the amount ofaerosol propellant usable in the composition depends on the particularaerosol propellant being used.

[0032] When surfactants are used in insecticide formulations of theinvention, the propellant preferably comprises a hydrocarbon propellantcontaining, for example, a mixture of propane and isobutene. Othersuitable hydrocarbon propellants would also be known to one skilled inthe art. One suitable propellant is available from Aeropres Corporationunder the tradename Aeropres 70 (A-70), and is formulated to reach 70pounds of pressure at room temperature. The concentration of thepropellant in the insecticide formulation containing surfactants isapproximately 10-20% by weight of the composition.

[0033] The insecticides of this invention may be applied in the form ofan aerosol spray or as an aerosolized foam. The insecticides areeffective against a variety of insects including ants, roaches, flies,spiders and similar insects, while at the same time having a toleranceallowing for their use on food and in food preparation areas.Furthermore, the insecticide formulations are non-repellant to termites.

[0034] Advantageously, because of the solubilizing power of theiso-paraffinic hydrocarbon carrier for the deltamethrin, the aerosolinsecticide formulation not containing foaming agent(s) may be appliedwithout mixing or shaking immediately prior to the application. Asdiscussed above, insecticide formulations containing foaming agent(s) doneed to be mixed by shaking immediately prior to application.

[0035] This invention is further demonstrated by the following examples,which should be taken as illustrative and not limiting in any manner.

EXAMPLE I

[0036] 0.5 grams of deltamethrin were dissolved with stirring into 359.5grams of ISOPAR® E solvent. The mixture was stirred at room temperature,until the deltamethrin was dissolved. The mixture was added to anaerosol can, a valve installed, and 540.0 grams of liquefied petroleumgas (aerosol propellant) were added. The insecticide was stored in theaerosol can for several months and remained a uniformly mixed effectiveinsecticide.

EXAMPLE II

[0037] 121.0 grams of VISTA LPA-210® solvent were heated to 120° F. and0.5 grams of deltamethrin was added to the solvent with mixing untildissolved. 175.5 grams of ISOPAR-E® solvent was added with stirring. Themixture was added to an aerosol can, a valve installed, and 603.0 gramsof liquefied petroleum gas (aerosol propellant) were added. Theinsecticide was stored in the aerosol can for several months andremained a uniformly mixed effective insecticide.

EXAMPLE III

[0038] 923.0 grams of VISTA LPA-210® solvent were heated to 120° F. and1.0 gram of deltamethrin was added to the solvent with mixing untildissolved. 660.0 grams of ISOPAR-E® solvent was added with stirring. Themixture was added to an aerosol can, a valve installed, and 66.0 gramsof carbon dioxide (aerosol propellant) were added. The insecticide wasstored in the aerosol can for several months and remained a uniformlymixed effective insecticide.

EXAMPLE IV

[0039] 1119.0 grams of deionized water were heated to 180° F. and 0.96grams of deltamethrin were added to the water with stirring for about 30minutes, until dissolved. After the deltamethrin was dissolved, 120grams of sodium laureth sulfate, 24 grams of cocamide DEA and 96 gramsof cocamidopropyl betaine were added to the mixture until well mixed.The mixture was added to an aerosol can, a valve installed, and 240grams of A-70™ (aerosol propellant) were added. The insecticide wasstored in the aerosol can. The insecticide required shaking immediatelyprior to use. If the insecticide is used for an extended period of time,it may also be necessary to shake the insecticide formulation at variousintervals during use.

[0040] One of the major advantages of the foaming aerosol-basedinsecticide compositions of the invention is that the formulations aredo not require separate mixing steps prior to use. Unlike many of thefoaming insecticide compositions of the prior art which requiredadditional processing steps to first mix the foaming agent(s) togetherand to then mix the foaming agent(s) into the remaining ingredients ofthe composition prior to use, the foaming insecticide compositions ofthe present invention are ready to use, and only require shaking of theinsecticide compositions immediately prior to use.

What is claimed is:
 1. An aerosol-based insecticide composition usable on food or in a food preparation area comprising: a) an insecticide comprising: i) 0.01 to 2.0 percent by weight of an active ingredient having a tolerance for use on food based on the total weight of the insecticide; and ii) 80 to 99.98 percent by weight of a branched aliphatic hydrocarbon carrier, with a general empirical formula of C_(n)H_(2n+2) based on the total weight of the insecticide; and b) an effective amount of an aerosol propellant that is compatible with said insecticide.
 2. An insecticide composition according to claim 1, wherein said active ingredient having a tolerance for use on food comprises a pyrethrin.
 3. An insecticide composition according to claim 2, wherein said pyrethrin comprises deltamethrin.
 4. An insecticide composition according to claim 3, wherein the deltamethrin is non-repellant to termites.
 5. An insecticide composition according to claim 3, wherein the deltamethrin has a concentration of 0.01 to 0.5 percent by weight based on the total weight of the insecticide.
 6. An insecticide composition according to calm 5, wherein the deltamethrin has a concentration of 0.1 to 0.3 percent by weight based on the total weight of the insecticide.
 7. An insecticide composition according to claim 1, wherein the branched aliphatic hydrocarbon carrier comprises a mixture of C₈ and C₉ branched isoparaffins.
 8. An insecticide composition according to claim 1, wherein the concentration of aromatic hydrocarbons in the carrier is less than 1 percent by weight of the carrier.
 9. An insecticide composition according to claim 1, wherein the aerosol propellant is selected from the group consisting of carbon dioxide and liquefied petroleum gas.
 10. A method of exterminating insects, which method comprises contacting the insects with an aerosol spray of an insecticide composition comprising: a) 0.01 to 2.0 percent by weight of an active ingredient having a tolerance for use on food based on the total weight of the insecticide; and b) 80 to 99.98 percent by weight of a branched aliphatic hydrocarbon carrier, with a general empirical formula of C_(n)H_(2n+2), based on the total weight of the insecticide; wherein said insecticide composition is charged to an empty aerosol can and an effective amount of an aerosol propellant is added to said can.
 11. The method of claim 10, wherein said active ingredient having a tolerance for use in food comprises a pyrethrin.
 12. The method of claim 11, wherein said pyrethrin comprises deltamethrin.
 13. The method of claim 12, wherein the deltamethrin is non-repellant to termites.
 14. The method of claim 12, wherein the deltamethrin has a concentration of 0.01 to 0.5 percent by weight based on the total weight of the insecticide.
 15. The method of claim 14, wherein the deltamethrin has a concentration of 0.1 to 0.3 percent by weight based on the total weight of the insecticide.
 16. The method of claim 10, wherein the branched aliphatic hydrocarbon carrier comprises a mixture of C₈ and C₉ branched isoparaffins.
 17. The method of claim 10, wherein the concentration of aromatic hydrocarbons in the carrier is less than 1 percent by weight of the carrier.
 18. The method of claim 10, wherein the aerosol propellant is selected from the group consisting of carbon dioxide and liquefied petroleum gas.
 19. A ready-to-use foaming aerosol-based insecticide composition comprising: a) one or more surfactants; b) an active ingredient, wherein said active ingredient comprises deltamethrin; c) a carrier; and d) an aerosol propellant.
 20. The foaming insecticide composition of claim 19 wherein said one or more surfactants are selected from the group consisting of sodium laureth sulfate, cocamide DEA, cocamidopropyl betaine, and mixtures of the foregoing.
 21. The foaming insecticide composition of claim 20 wherein said one or more surfactants consist essentially of 50% by weight sodium laureth sulfate, 10% by weight cocamide DEA, and 40% by weight cocamidopropyl betaine.
 22. The foaming insecticide composition of claim 19 wherein said carrier comprises deionized water.
 23. The foaming insecticide composition of claim 19 wherein said aerosol propellant comprises a hydrocarbon propellant.
 24. The foaming insecticide composition of claim 23 wherein said hydrocarbon propellant comprises a mixture of propane and isobutane.
 25. The foaming insecticide composition of claim 19 wherein said insecticide composition is non-repellant to termites.
 26. A ready-to-use foaming aerosol-based insecticide composition that is non-repellant to termites comprising: a) 10-25% by weight of one or more surfactants selected from the group consisting of sodium laureth sulfate, cocamide DEA, cocamidopropyl betaine, and mixtures of the foregoing; b) 0.01-2% by weight deltamethrin c) 55-75% by weight of a carrier; and d) 10-20% by weight of an aerosol propellant.
 27. A foaming insecticide composition according to claim 26 wherein said carrier comprises deionized water.
 28. A foaming insecticide composition according to claim 26 wherein said aerosol propellant comprises a hydrocarbon propellant.
 29. A foaming insecticide composition according to claim 28 wherein said hydrocarbon propellant comprises propane and isobutane.
 30. A foaming insecticide composition according to claim 26 wherein said one or more surfactants consist essentially of 50% by weight sodium laureth sulfate, 10% by weight cocamide DEA, and 40% by weight cocamidopropyl betaine. 